That’s what I was thinking. IRCC is like “if you can travel, do it”.The emails you are referring to Actually say that you should continue to make plans to land in canada in 2020 and thats what the OP is doing.
“If your PR application was approved before or on March 18, 2020, you are allowed to travel to Canada. Please read about the public health measures below. If circumstances allow, we encourage you to continue to make plans to land in Canada in 2020.“
They do not specify the length of stay required
I’m hoping that the Customs Officer will have the same opinion.
From what I heard is the land border way more stringent then airports.